Abstract: A valve actuation system is disclosed for an internal combustion engine. The system may have a gas exchange valve, a rocker arm pivotally connected to a shaft, a pushrod, a lash adjuster disposed in the pushrod. The system may also have an adjusting screw disposed in the rocker arm and configured to engage and fluidly supply the lash adjuster. The adjusting screw may include a shaft having a threaded outer annular surface, and a head connected to the shaft and having a rounded outer surface and a flat end face. The adjusting screw may also include an axial passage passing through the flat end face, a radial passage formed in the shaft and extending from the threaded bore of the rocker arm to the axial passage, and at least one radial groove formed in the rounded outer surface of the head and passing through the axial passage.

Abstract: An internal combustion engine includes a cylinder block defining a lifter bore, and a valve lifter assembly positioned at least partially within the lifter bore and configured to actuate a push rod. The assembly includes a valve lifter and an angular displacement-limiting clip. A cutout is formed on a proximal end of the valve lifter and includes a channel and a taper. The valve lifter is rotatable out of alignment with a cam, and the clip limits angular displacement of the valve lifter via contacting a wall portion of the cylinder block. First and second fillets of the clip are positionable within the cutout, such that the taper provides a clearance for inhibiting impingement of the valve lifter upon the fillets.

Abstract: An internal combustion engine includes an engine housing defining a cylinder, and a first and a second gas exchange valve for the cylinder, positioned within the engine housing. The engine further includes a valve actuating mechanism having a first and a second valve lifter reciprocating within adjacent lifter bores to actuate the first and second gas exchange valves. Each of the first and second valve lifters includes an end cap having a misalignment limiting projection, limiting rotation of the valve lifter in response to dynamic perturbation.

Abstract: An internal combustion engine includes an engine housing defining a cylinder, and a first and a second gas exchange valve for the cylinder, positioned within the engine housing. The engine further includes a valve actuating mechanism having a first and a second valve lifter reciprocating within adjacent lifter bores to actuate the first and second gas exchange valves. Each of the first and second valve lifters includes an end cap having a misalignment limiting projection, limiting rotation of the valve lifter in response to dynamic perturbation.

Abstract: An internal combustion engine includes a cylinder block defining a lifter bore, and a valve lifter assembly positioned at least partially within the lifter bore and configured to actuate a push rod. The assembly includes a valve lifter and an angular displacement-limiting clip. A cutout is formed on a proximal end of the valve lifter and includes a channel and a taper. The valve lifter is rotatable out of alignment with a cam, and the clip limits angular displacement of the valve lifter via contacting a wall portion of the cylinder block. First and second fillets of the clip are positionable within the cutout, such that the taper provides a clearance for inhibiting impingement of the valve lifter upon the fillets.

Abstract: A clip includes a one-piece metal body having a holder and an attached hanger. The clip is configured to couple with a valve lifter to form a lifter assembly for varying the position of a valve in an internal combustion engine. The holder may be C-shaped, and the hanger may be U-shaped. The one-piece metal body further includes an anti-scuffing outer profile, and a first and a second fillet transitioning from the holder to the hanger, for diffusing stresses induced in the clip at an angular displacement-limiting stop position defined by contact between the hanger and a wall portion of a cylinder block. Related methodology is disclosed.